82 citations · 311 across the 36 of their papers we have counts for
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Quaternionic matrices: Unitary similarity, simultaneous triangularization and some trace identities
Dragomir Z. Djokovic, Benjamin H. Smith
We construct six unitary trace invariants for 2 by 2 quaternionic matrices which separate the unitary similarity classes of such matrices, and show that this set is minimal. We pro…
On orthogonal and special orthogonal invariants of a single matrix of small order
Dragomir Z. Djokovic
We study the structure of the algebra of polynomial invariants for the usual conjugation action of the complex special, SO_n, and general, O_n, orthogonal group on the space of tra…
On orthostochastic, unistochastic and qustochastic matrices
Oleg Chterental, Dragomir Z. Djokovic
We introduce qustochastic matrices as the bistochastic matrices arising from quaternionic unitary matrices by replacing each entry with the square of its norm. This is the quaterni…
Cyclic (v;r,s;lambda) difference families with two base blocks and v <= 50
Dragomir Z. Djokovic
We construct many new cyclic (v;r,s;lambda) difference families with v less than or equal 50. In particular we construct the difference families with parameters (45;18,10;9), (45;2…
Skew-Hadamard matrices of orders 188 and 388 exist
Dragomir Z. Djokovic
We construct several difference families on cyclic groups of orders 47 and 97, and use them to construct skew-Hadamard matrices of orders 188 and 388. Such difference families and…
Hadamard matrices of order 764 exist
Dragomir Z. Djokovic
We construct two Hadamard matrices of order 764. Both are of Goethals-Seidel type.